Aquisição, afasia e a hierarquia prosódica

Studies on language acquisition have shown that the child exhibits a top-down trajectory in the acquisition of the prosodic hierarchy, starting with the organisation of the upper (intonational) prosodic levels. Rhythmic readjustments and postlexical secondary stress are later acquisitions. Prosodic disturbances of aphasia and dysarthria have been connected to the question of brain-damage lateralisation and linguistic processing. Subjects damaged in their right hemisphere are said to be dysprosodic; they produce few Fo variations, Fo flattenning, slow tempo. Prosody is said to be reasonably preserved in Broca´s subjects and well preserved in fluent (Wernicke) aphasia subjects. A comparative study was carried out with two subjects, one aphasic and one dysarthric. Some prosodic difficulties were observed in the speech of fluent aphasic subjects, related to the prosodic hierarchy, to the metrical grid and to syllable structure, respectively. On the other hand, the correct placement of pauses in the frontiers of upper domains of the dysarthric subject shows preservation of the prosodic hierarchy. Pitch-direction is also preserved, with short pitch-range. In both cases, the upper domains of the prosodic hierarchy are preserved.